Screw driver



E. OJALVO SCREWDRIVER Oct. 27, 1942.

Filed Jan. 13, 1941 Edmond @j'd/V max Patented Oct. 27, 1942 aaoasosUNITED STATES PATENT OFFICE SCREW DRIVER Edmond Ojalvo, New York, N. Y.Application January 13, 1941, Serial No. 374,199 1 Claim. (Cl. 145-50)This invention relates to magnetic screwdrivers, and particularlyalthough not exclusively to tools of this category employing permanentmagnets.

Cognizance is taken of certain electromagnetic screwdrivers adapted tomagnetically retain a screw against the blade of the tool,such devices,however, being generally intricate in structure and too costly forpractical purposes. There are also other types of screwdriverscontaining mechanical gripping means for holding the screw head in placeagainst the blade, these being also generally relatively expensive andat times difllcult to operate. It is primarily within the contemplationof my invention to provide a screwdriver with magnetic means of such anature as to not only enable the screw to be properly retained in placeagainst the blade, but also maintained in such position during thedriving operation.

It is a common occurrence in the operation of a screwdriver that if theaxis of the tool and that of the screw are not perfectly aligned, theblade will either slip oii, or the screw driven in at an undesiredangle. It is another object of this invention to provide meansassociated with a screwdriver for at all times maintaining the screw inproper relation with respect to the blade during the operative use ofthe tool.

It is another object of this invention to enable a device of the abovecategory to be adiustably adapted for use with screws of difierent slotdepths, whereby the instrument can be most effectively employed for itsintended purpose.

Another object of this invention is to provide a screwdriver with adriving surface of extended area to constitute a saddle or abutmentmember, whereby it will engage substantially the entire head of thescrew, or a goodly portion thereof. In this manner my invention enablesa greater effective driving force to be applied against the screw whilebeing operatively driven. It is another object of my invention toprovide interchangeable saddles for screws with different sized andshaped heads, whereby both the blade and the saddle will engage asubstantial portion of the screw head during the driving operation.

Other objects, features and advantages will appear from the drawing anddescription hereinafter given.

Referring to the drawing,

Figure 1 is a fragmentary elevation of a screwdriver showing one form ofmy invention,-il1ustrated in operative relation to a screw sliozzn bydot-dash lines. I

Figure 2 is a fragmentary section of Figure 1 taken along line 2 2.

Figure 3 is a transverse section of Figure 2 taken along line 3-3.

Figure 4 is a fragmentary perspective of a screwdriver constituting amodified form of my invention.

Figure 5 is a transverse section of Figure 4 taken substantially alongline 5-5.

Figure 6 is a fragmentary elevation of a screwdriver illustratinganother modified form of my invention showing its operative relation toa screw shown by dot-dash lines.

Figure 7 is a section of Figure 6 taken substan: tially along line 1-1.

Figure 8 is a fragmentary section similar to that of Figure 7, showinganother position of the saddle as adapted for a smaller screw, and

Figure 9 is a sectional plan of Figure 8 taken I along line 9-9.

In the drawing, the blade I0 of the screwdriver I I contains,

Positioned blade are the two magnetic members 13 and It, said membersbeing preferably permanent magnets that may be magnetically attached tothe blade. The said members contain two apertured portions i5 and iii insubstantial registry with the apertured portion i2 of the blade; andextending through apertures I2 and G5 or the blade and member l3,respectively, is the shank of the bolt H, the head thereof beingdisposed within aperture 1 6. In threaded engagement with the outwardlyprotruding end of bolt I"! is the wing nut I8. The arrangement is suchthat the said magnetic members i 3 and M can be adjustably movedlongitudinally of the blade within-the limits of the aperture 15, andplace.

In the operation of the tool disclosed in Figures 1 to 3, the members 13and I4 are adjustably positioned in the manner aforesaid so that theblade will protrude forwardly from the front edges is and 20 of themembers a distance corresponding to the depth of the slot of a screw 2|preferably although not necessarily along the medial portion thereof, anaperture 12. against the opposite flat sides of the fixedly secured inscrewdriver. Not only. does the magnetic construction serve to hold thescrew in place, but the surfaces or ends l9 and 2|) of these members,being in abutment with the screw, serve to cooperate with the blade ineffectuating the driving operation, as distinguished from the commontype of screwdriver wherein only the blade is in driving engagement withthe screw. Furthermore, the members l3 and i4 actually act as saddlesfor supportingthe head of the screw 2|, and preventing it fromaccidentally tilting out of alignment with the blade, or from beingdriven at an undesired angle into the work.

The combination of the magnetic members l3 and I4 and the blade ID inthe manner disclosed constitutes a means of holding the head of any oneof a number of differently sized screws firmly and properly in positionfor the driving operation.

Figures 4 and 5 show a modified form of my invention wherein instead ofemploying two separate magnetic elements I3 and I4, a single U-shapedmagnetic member 22 is placed over the blade 23 of the screwdriver 24,the opposite legs of the magnet flanking the blade as shown. In theparticular embodiment disclosed in these figures, the magnet containstwo axially aligned holes 25 and 26, the latter being threaded. A screw21 extends through the two said holes 25 and 26 as well as the aperture28 in the blade, the lower portion of the screw being in threadedengagement with hole 26,,the arrangement is somewhat simpler and morestreamlined than that of the first-mentioned form of my invention, inthat a single magnet is employed, and no wing nut is used, but in placethereof a screw member having a head only slightly protruding above themagnet and adapted for operatively receiving either a screwdriver or athin coin to manipulate the screw and adjustably position member 22along blade 23.

Figures 6, 7, 8 and 9 show still another modification of my invention inwhich the blade 29 of the screwdriver 39 is flanked by two magneticmembers 3| and 32, the former containing a threaded stud 33 extendingthrough apertured portion 34 of the blade and the hole 35 in themagnetic member 32. A nut 36 is in threaded engagement with theprotruding portion of the stud 33, whereby the assembly of the magneticmembers 3| and 32 may be adjustably moved along blade 29 within thelimits of apertured portion 34. The screwdriver 3|! contains a shoulder31, and disposed between said shoulder and the rear ends 33 and 39 ofthe magnetic members 3| and 32 is a preferably helical spring 40 mountedover the blade.

Normally said spring urges the magnetic members forwardly to theposition shown in Figure 8 where the foremost wall 4| of the aperture 34is in abutment with stud 33. Thus, when the nut 36 is in its loose orinoperative position on the stud, the said spring 49 will be freelyurging the magnetic members forwardly so that the forward walls 42 and43 thereof are in yieldable abutment with the head 44 of a'screw 45being driven by the tool. It is of course obvious that this conditionwill only prevail if the tip of the blade 29 projects forwardly adistance preferably slightly less than the depth of the slot in thescrew head 44. The screwdriver can hence be conveniently manipulatedwith the said screw 33 loosely mounted as indicated, the walls 42 and 43cooperating with the blade to eifect a firm and effective drivingaction.

Should it, however, be desired to adjustably fix the magnetic members 3|and 32 at a predetermined position on the blade, that can be readilydone by moving said members against the action of spring 49, and thentightening said nut 36. In this manner the screwdriver will be set foroperative use with screws of predetermined dimensions.

It will be further observed that the shape of the walls 42 and 43constituting abutments or saddles for the screw are, in theformillustrated, concave, so as to be adapted for operative use with theround headed screw 44. It is of course obvious that the magnetic members3| and 32 can be readily removed and replaced with other similar membershaving differently proportioned and shaped forward walls adapted toserve as saddles for various sizes and types of screws.

It is understood that the various embodiments above described and shownin the drawing are illustrative of my invention and not employed by wayof limitation, inasmuch as numerous changes and modifications may bemade within the scope of the appended claim without departing from thespirit of this invention.

What I claim is:

In a screwdriver, a blade member, an abutment member mounted upon theforward portion of the blade member and normally freely movablelongitudinally with respect thereto, a longitudinally disposed aperturein said blade member, an outwardly directed shoulder in the rear ingsaid blade member and located in abutment with said shoulder and therear portion of said abutment member for urging said abutment memberforwardly, screw means for securing said abutment member to the blademember at a predetermined point .therealong, said screw means containinga shank portion engaging said abutment member and extending transverselythrough said aperture, the sliding movement of said abutment member andsaid screw means being limited by the front and rear walls 'ofsaidaperture, the front portion of said abutment member being disposedrearwardly from the forward end of the blade and being shaped forabuting engagement with the head of a coacting screw.

EDMOND OJALVO.

